Does Sugar Make Your Heart Sweeter?

April 14, 2014 -- Celebrity Snickers pitchmen Joe Pesci and Don Rickles show that “You’re not you when you’re hungry.”

In a Snickers commercial, Pesci and Rickles make rude comments to strangers they meet at a party. Now a new study suggests that the commercial might have a hint of truth: Hunger really may lead to greater aggression.

In the study, though, the aggression was directed not toward strangers, but toward someone much closer -- your spouse.

The researchers found that lower blood glucose levels predicted more aggression toward spouses, although some psychologists are skeptical of that theory.

Glucose is the sugar in your blood that your body uses for fuel.

“Numerous studies have found a relationship between low glucose levels and poor self-control,” the researchers write in the Proceedings of the National Academy of Sciences. “When glucose levels are low, people have more difficulty controlling their attention, regulating their emotions, and overriding their aggressive impulses. Some evidence suggests that low glucose levels might even increase the risk of violent criminal behavior, including spousal abuse.”

Hunger and Anger

The study involved 107 married heterosexual couples. They measured their blood glucose levels with a monitor twice daily for 3 weeks, before breakfast and before bedtime.

This is where the study gets a little unusual: Besides a glucose monitor, participants received a voodoo doll and 51 pins. The doll was supposed to represent their spouse. Every evening, in private, the participants stuck pins in the doll. How many depended on how angry they felt toward their spouse.

Voodoo dolls might seem like an unusual research tool, but study researcher Brad Bushman, PhD, says an earlier study by one of his collaborators showed the worth of their use.

At the end of the 3 weeks, the couples came back into the lab, where they were told they were going to play a computer game against their spouse. The goal: Be the first one to press a button after a square on the screen turned red. The winner would then get to blast the loser with loud noise through headphones. The noise was a mixture of irritating sounds, such as fingernails scratching a chalkboard and dentist drills. The winners got to pick the noise level and duration. If they were feeling warm and fuzzy about their spouse, they could choose silence instead of noise.